A computational fluid dynamics analysis of the distraction forces experienced by stent-grafts following fenestrated Endovascular Aneurysm Repair

Jones, Steven (2016) A computational fluid dynamics analysis of the distraction forces experienced by stent-grafts following fenestrated Endovascular Aneurysm Repair. Doctor of Medicine thesis, University of Liverpool.

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Abstract

Introduction One option for repair of abdominal aortic aneurysms with inadequate length of infrarenal neck is fenestrated Endovascular Aneurysm Repair. Significant complications may be caused by stent-graft migration and component distraction which are both resisted by fixation force and provoked by haemodynamic distraction force. The hypotheses tested in this thesis are that larger angulation of vessels is associated with greater distraction force and that greater distraction force is associated with higher incidence of migration and component distraction. Method Interobserver variation of a new method of angle measurement was compared with the standard method currently in use in our unit. Computer models of complete fenestrated stent-grafts and their individual components (proximal body, distal body and limb extensions) were then constructed based on the postoperative computed tomography scans of 54 patients. Computational Fluid Dynamic analysis in steady state was used to quantify the distraction force acting on each device. Blood pressure was kept constant at 160mmHg and the impact of morphological features upon distraction force was assessed. To test the second hypothesis, patient-specific blood pressures were used to obtain in situ distraction forces that were then related to the incidence of migration and component distraction. Results There were no significant differences between the old and new methods of angle measurement (p=.723, WSR). Inlet cross-sectional area (XSA) exhibited a strong, positive correlation with total RDF in complete stent-grafts, proximal body and distal body components. Outlet angulation ≥45° was significantly associated with greater total RDF in complete stent-grafts and limb extension components (Median total RDF in complete stent-grafts with angle

Item Type:	Thesis (Doctor of Medicine)
Additional Information:	Date: 2016-02-19 (completed)
Subjects:	?? RD ??
Divisions:	Faculty of Health and Life Sciences
Depositing User:	Symplectic Admin
Date Deposited:	31 Aug 2016 09:31
Last Modified:	17 Dec 2022 02:27
DOI:	10.17638/02052119
URI:	https://livrepository.liverpool.ac.uk/id/eprint/2052119